Analog sound velocity calculator

Abstract

An analog apparatus for determining the velocity of sound at a selected position in a liquid media is provided with a means for representing the conductivity, temperature, and depth of the position in the form of analog voltages, and is further provided with an analog calculating means receiving each of the voltages for calculating the velocity of sound as a function of conductivity, temperature, and depth. The sound velocity may be calculated at a succession of positions to provide a sound velocity versus depth profile of the liquid media.

What is claimed is: 
     
       1. Apparatus for enabling the passive determination of the velocity of sound at various levels in a liquid media comprising: means for passively sensing the temperature, conductivity, and depth of the liquid media at various levels;   means for representing said sensed temperature in the form of a first voltage, for representing said sensed conductivity in the form of a second voltage, and for representing said sensed depth in the form of a third voltage;   analog calculating means receiving said first, second, and third voltages for providing an analog output voltage in real time which represents the velocity of sound at said levels.   
     
     
       2. An apparatus for enabling the determination of sound at various levels in a liquid media comprising: means for passively sensing the temperature, conductivity, and depth of the liquid media at various levels;   means for representing said sensed temperature in the form of a first voltage, for representing said sensed conductivity in the form of a second voltage, and for representing said sensed depth in the form of a third voltage;   analog calculating means receiving said first, second, and third voltages for providing an analog output voltage which represents the velocity of sound at said levels, said analog calculating means comprising: a first analog means receiving said first voltage for providing a fourth voltage, which comprises said first voltage multiplied by a first constant;   a second analog means receiving said first voltage and said second voltage for providing a fifth voltage which comprises the sum of: said first voltage multiplied by a second constant, said second voltage multiplied by a third constant, and a fourth constant;   a third analog means receiving said fourth voltage and said fifth voltage for providing a sixth voltage which comprises the product of: said fourth voltage, said fifth voltage, and a fifth constant;   a fourth analog means receiving said second voltage and said third voltage for providing a seventh voltage which comprises the sum of: said second voltage multiplied by a sixth constant, said third voltage multiplied by a seventh constant, and an eighth constant;   a fifth analog means receiving said sixth voltage and said seventh voltage for providing said analog output voltage representing said sound velocity, said analog output voltage comprising the sum of: said sixth voltage multiplied by a ninth constant and said seventh voltage; and   said first analog means comprises a first operational amplifier, a first resistor coupled in parallel with said first operational amplifier, and a second resistor coupled in series with said first operational amplifier, said first constant comprising the ratio of said first resistor to said second resistor.     
     
     
       3. The apparatus of claim 2 wherein: said second analog means includes a second operational amplifier, a third resistor coupled in parallel with said second amplifier, and fourth and fifth resistors coupled in series with said second operational amplifier, said second constant comprising the ratio of said third resistor to said fourth resistor and said third constant comprising the ratio of said third resistor to said fifth resistor.   
     
     
       4. The apparatus of claim 3 wherein: said fourth analog means includes a third operational amplifier, a sixth resistor coupled in parallel with said third operational amplifier, and seventh and eighth resistors coupled in series with said third operational amplifier, said sixth constant comprising the ratio of said sixth resistor to said seventh resistor, and said seventh constant comprising the ratio of said sixth resistor to said eighth resistor.   
     
     
       5. The apparatus of claim 4 wherein: said fifth analog means includes a fourth operational amplifier, a ninth resistor coupled in parallel with said fourth operational amplifier, and a tenth resistor coupled in series with said fourth operational amplifier, said ninth constant comprising the ratio of said ninth resistor to said tenth resistor.   
     
     
       6. The apparatus of claim 5 wherein: said first and second resistors are respectively selected so that said first constant is 2.5.   
     
     
       7. The apparatus of claim 6 wherein: said third, fourth, and fifth resistors are respectively selected so that said second constant is 0.4572 and said third constant is 2.030, said fourth constant being 12.675.   
     
     
       8. The apparatus of claim 7 wherein: said sixth, seventh and eighth resistors are respectively selected so that said sixth constant is 5.126 and said seventh constant is 0.3392, said eighth constant being 16.813; said ninth and tenth resistors are respectively selected so that said ninth constant is 1.837 and;   said third analog means is selected so that said fifth constant is 0.1.   
     
     
       9. The apparatus of claim 3 wherein: said passive sensing means includes a free-fall probe which is dropped through a succession of levels in said liquid media for passively sensing the temperature and conductivity of said liquid media at each of said levels and the depth of each level;   said analog calculating means receives said first, second and third voltages for providing a succession of output voltages which represent the sound velocity at each of said successive levels; and   a graphic recording system receives each of said output voltages for providing a graphic representation of the sound velocity at said levels and the depth of each of said levels.   
     
     
       10. The apparatus of claim 9 wherein said apparatus is adapted to provide said graphic representation in real time. 
     
     
       11. The apparatus of claim 10 wherein: said free-fall probe is adapted to drop through said liquid media at a constant rate, and said apparatus is adapted to calculate and represent said sound velocity at selected time intervals as said probe is dropping. 
     
     
       12. The apparatus of claim 11 wherein: said liquid media comprises an ocean body.